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Does the 2 bar map sensor on a Whipple Supercharger adjust the fuel for more air going into the supercharger like when a larger throttle body is used, or more efficient air filter?
Does the tune need to be adjusted to allow for more fuel with the increased amount of air?
I know the map sensor reads the amount of boost or pressure but I don't know what the computer does with the information.
 

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Does the 2 bar map sensor on a Whipple Supercharger adjust the fuel for more air going into the supercharger like when a larger throttle body is used, or more efficient air filter?
Does the tune need to be adjusted to allow for more fuel with the increased amount of air?
I know the map sensor reads the amount of boost or pressure but I don't know what the computer does with the information.
The MAP sensor’s output, in conjunction with IAT’s output (and engine RPM), is used to calculate the mass of the air charge coming into the engine and filling the combustion chambers.

That calculation is used to look up injector pulse width values from preset volumetric efficiency tables that are specifically for that engine (in its stock form). Any change to the engine that affects its VE has to be accounted for by making corresponding changes in those preset VE tables stored in the PCM.

That is done by modifying the tune. It doesn’t need to be told to increase fuel flow per se, it just needs to have those VE tables updated so that when the PCM looks up how much fuel to mix in with its calculated air charge, it will find the corresponding injector pulse width value(s) in that VE lookup table.

In other words, by making those changes to the VE tables to account for s/c, the PCM will automatically adjust the fuel accordingly, when applicable.

That’s my understanding of the whole thing, hopefully someone will chime in and correct me if i am incorrect with any of this.
 

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Just adding a 2 bar map sensor and a supercharger will make the car set a bunch of codes and it may not even run.
Nuke is on the right track for a pre-2008 car or so. For the newer cars it's even more complicated as there are fuel mass vs pulsewidth and inverse tables as well as a neural network enabled. The VE tables aren't even used.

Also, the map sensor must be re-scaled in the tune.

Short answer - yes, the tune must be adjusted.
 

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Well of there’s one thing I can’t abide, it’s disseminating out-of-date information, so it clear there is only one option for me now - get a supercharger and put it on The Bacon Hauler, thereby forcing me to get up to date with my speed density operation info in order to tune the new blower for my particular needs.

Now, how to get the sizable amount of money I’ll need to buy all the hardware becomes my main issue...I wonder if I could get a GoFundMe thing set up to cover that... :unsure:
 

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It also depends on how you want to tune to run...NN on or NN off (speed density which uses VE tables and waaay longer to tune). With NN on (PCM takes care of PT fueling), you basically tweak the injector tables to get fueling dialed in so the commanded and actual AFR align (need to pull timing though as stock tables are a bit much initially). Typically, WOT theshold is set (based of pedal position in volts) so that PE (power enrichment) kicks in just when boost does. The PE table is a fuel adder to stoich which is based off aircharge (calculated from MAP) and RPM. The PE aircharge values need to be scaled to account for the additional air produced by the supercharger. On HP tuners there is a switch that allows PE to be based off Aircharge or Pratio. Anyways that is a super distilled way (there is a lot more to it) of tuning via NN on. BTW only way you will be able to do this by yourself is with HP tuners, SCT and Diablo Sport don't give you control of the tuned unless you have their tuner software.
 

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Well of there’s one thing I can’t abide, it’s disseminating out-of-date information, so it clear there is only one option for me now - get a supercharger and put it on The Bacon Hauler, thereby forcing me to get up to date with my speed density operation info in order to tune the new blower for my particular needs.

Now, how to get the sizable amount of money I’ll need to buy all the hardware becomes my main issue...I wonder if I could get a GoFundMe thing set up to cover that... :unsure:
Here you go...

The McIver's: Hollis' Lemonade Stand!
 

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Lemonade?! I thought that lemons were phased out by the Acai berry? Binomial marketing is where it is at.

He has to start somewhere...
 

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Discussion Starter #9

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983203


A Guy
 

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What is your GoFundMe page called? I will kick in a few $$. I will also take a large Lynchburg Lemonade when you get your stand open.

Ingredients
All kidding aside, I’m far too immature and impulsive to have a super charger on my car. I can’t go a month without getting stopped for speeding, they’d have me under the jail if I got blown, err, if my car were blown...you know what I mean!
 

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Actually the biggest problem with a super charger is trying not to let the tires smoke when you are a little too aggressive applying the pedal...especially when taking a turn.
 

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Actually the biggest problem with a super charger is trying not to let the tires smoke when you are a little too aggressive applying the pedal...especially when taking a turn.
well if Hollywood has taught me anything, it’s that belt driven superchargers can be turned on/off with a toggle switch on the dash, so I would just be sure and not switch mine on until I was well under way, this avoiding the ability to smoke the tires.

also, when trying to extricate one’s self from a hastily dug grave in which you’ve been dumped inside your own vehicle, it’s best to flip the supercharger on right off the bat to climb out.

and for anyone that thinks all this sounds crazy, let me direct you to a little movie called Lone Wolf McQuade, starring Chuck Norris!
 

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All kidding aside, I’m far too immature and impulsive to have a super charger on my car. I can’t go a month without getting stopped for speeding, they’d have me under the jail if I got blown, err, if my car were blown...you know what I mean!
A friend of mine told me he pulled a car over the day before yesterday. He said the guy was doing 91 in a 45 zone, and told him he was late for work. Well, he didn't make it to work, he went straight to jail, and did not pass go...
 

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A friend of mine told me he pulled a car over the day before yesterday. He said the guy was doing 91 in a 45 zone, and told him he was late for work. Well, he didn't make it to work, he went straight to jail, and did not pass go...
like my grand pappy told me before he left this world, “Nuke, doubling up on the speed limit is a bad idea, but doing it inside the city limits is plumb stupid. Now go call your grandma and tell her where I am so she can come bail me out...again.
 

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well if Hollywood has taught me anything, it’s that belt driven superchargers can be turned on/off with a toggle switch on the dash,.....
Then what are you waiting for...get one so you can go bat ship crazy!

983252
 

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It also depends on how you want to tune to run...NN on or NN off (speed density which uses VE tables and waaay longer to tune). With NN on (PCM takes care of PT fueling), you basically tweak the injector tables to get fueling dialed in so the commanded and actual AFR align (need to pull timing though as stock tables are a bit much initially). Typically, WOT theshold is set (based of pedal position in volts) so that PE (power enrichment) kicks in just when boost does. The PE table is a fuel adder to stoich which is based off aircharge (calculated from MAP) and RPM. The PE aircharge values need to be scaled to account for the additional air produced by the supercharger. On HP tuners there is a switch that allows PE to be based off Aircharge or Pratio. Anyways that is a super distilled way (there is a lot more to it) of tuning via NN on. BTW only way you will be able to do this by yourself is with HP tuners, SCT and Diablo Sport don't give you control of the tuned unless you have their tuner software.
Thanks for the info ChallyTatum! Is it better to tune with the NN on or off? Which way would result in a better tune with less time involved?
 

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Unless running a big cam, most seem to tune with NN on but most folks swear tunes with it off give better results.
 
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